1. Field of the Invention
The present invention relates to a fuel tank assembly for a motorcycle, and to a motorcycle incorporating the same. More particularly, the present invention relates to a fuel tank assembly having a fuel tank disposed substantially along a seat rail, to a fuel pump unit disposed in the fuel tank via a mounting flange arranged below the seat rail, and to a motorcycle incorporating the same.
2. Description of the Background Art
There is a known structure in which a fuel tank is located below a seat of a vehicle (motorcycle) and a fuel pump is mounted in the fuel tank. An example of such structure is disclosed in Japanese Published Patent document 2007-118627.
The structure disclosed in the Japanese Patent Published Patent document 2007-118627 is an upper-mount type fuel pump, in which the fuel pump is installed in the upper portion of the fuel tank. Therefore, it is necessary to provide a space between the seat and the fuel tank for installing a fuel pipe therein, for supplying fuel to an engine of the vehicle. In view of a change of shape of the seat when an occupant sits thereon, it is necessary to ensure that a space is not smaller than a vertical width needed to arrange fuel piping. In addition, there is also a restriction on seat layout.
In order to ensure the degree of freedom of the seat layout, a structure is considered in which the space between the seat and the fuel tank is made minimal. Such structure corresponds to a lower-mount type fuel pump, where a fuel pump is mounted in the lower portion of the fuel tank.
However, if the lower-mount type fuel pump is applied to the above-mentioned conventional example as it is, the fuel pump will be disposed right above the rear wheel. Since the rear wheel swings vertically, it is necessary to provide a sufficient interval between the rear wheel and the fuel pump unit including a fuel pump, a mounting flange, and a fuel piping. In addition, it is necessary to avoid interference with gravel thrown up by the rear wheel.
The present invention has been made to overcome the drawbacks of existing fuel tank assemblies and in-tank fuel pumps. In view of the above difficulties with the known designs, in order to ensure the degree of freedom of seat layout, even a vehicle in which a fuel pump is lower-mounted in a fuel tank needs to have a fuel tank assembly in which a fuel pump unit does not interfere with a rear wheel or gravel or the like thrown up by the rear wheel during operation of the vehicle.
Accordingly, it is one of the objects of the present invention to provide a fuel tank assembly in which a fuel pump is mounted in a lower portion of a fuel tank, and a fuel pump unit does not interfere with a rear wheel or gravel or the like thrown up by the rear wheel during operation of the motorcycle, while ensuring a high degree of freedom of seat layout.